In recent years, electronic book readers are becoming widely prevalent. As opposed to a liquid crystal display, a bi-stable electro-optical display used as a display of an electronic book reader does not require any backlight, and consumes power only when the contents on the screen are changed, and the bi-stable electro-optical display can turn off the power except when the contents on the screen are changed, and therefore, the bi-stable electro-optical display has an advantage in that it consumes small electric power (for example, see PTL 1).